I have packaged bees that were closer together and have not experienced
your concern. A couple of tips I have always followed.
 
1. Reduce the hive enterance and fill it with some green grass. Not too
tight, it will dry out a bit and the bees will remove it in a few hours.
 This tends to create a small space for the new bees to guard and also
create difficultly for bees to leave or robber bees to enter.
 
2. Install the packages late afternoon or early evening. At this time of
 day the bees stay in the hive and have all night to adjust to their new
 home.
 
Good luck!